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Military conflict took place during every year of the 20th Century. There were only short periods of time that the world was free of war. The total number of deaths caused by war during the 20th Century has been estimated at 187 million and is probably higher.

Instituted in the hope of avoiding war, appeasement was the name given to Britain’s policy in the 1930s of allowing Hitler to expand German territory unchecked. Most closely associated with British Prime Minister Neville Chamberlain, it is now widely discredited as a policy of weakness. Yet at the time, it was a popular and seemingly pragmatic policy.

The Second World War was the most destructive conflict in human history. Years of international tension and aggressive expansion by Fascist Italy and Nazi Germany culminated in the German invasion of Poland on 1 September 1939. Britain and France declared war on Germany two days later.